Question

Hellium takes 5 seconds to effuse from a hole of 10dm3 containers. How long would it take for oxygen to effuse from the some container at the same temperature and pressure? 

Answer 1

According to Graham's law of Effusion/diffusion

$r\propto\sqrt\frac{1}{M}$

Where $r=$ Rate of effusion

$M=$ Molar mass

Rate of effusion $=$ $\frac{Volume}{time}$

$\frac{Rate\>of\>He}{Rate\>of\>O_2}=\frac{M_{O_2}}{M_{He}}$

$\frac{\frac{10}{5}}{\frac{10}{T}}=\sqrt\frac{32}{4}$

$T=14.14\>seconds$